Choose Right Kinetis MCU

Hi everyone.I'm looking for a Kinetis MCU have a hardware enough for my project with requirement : 5/6 UART, 4 PCM, 1 USB ports, Fcyc >100MHZ, can support interface with SD card, SD/DDRAM.I looked on highest version of Kinestis but cant choose a MCU suitable.Please help me to choose right partThanks

One SAI: it has two TX pins I2S0_TX0/I2S0_TX1 and two receiver pins I2S0_RX0/I2S0_RX1, each pin can transfer/receive two analog channels, in other words, SAI can transfer 4 channel PCM and receive 4 channels PCM.

Hi Xiangjun RongThanks for your sugesstions.I checked with K66 MCU based on info you given me.I think SAI not affordable for my project, because it only support one mode in samtime.But we need an 4 PCM channel alternated with those pin( PCM_CLK, PCM_SYNC, PCM_OUT, PCM_IN) can be work alternated because I want to interface with 4 GSM module via PCM channel, example : module 1 transfer audio data to K66, module 2,3 and 4 receive audio from K66 same time.I think may be my though is wrong, because this's first time i try with K66 MCUI draw an block function which ma help you o understand my perposePlease review and give a suggest for me if canThank for your support

* PCM interface with module( only support master mode from this module)

can you tell me whether the GSM module is master or the GSM module is slave?

If all the GSM module is slave, i suppose that you can use the kinetis with two SAI modules for example K28. One SAI module can interface with two GSM slave, for example, connect PCM_CLK/PCM_SYNC signals of K28 SAI to two GSM module respectively, connect the I2S0_TX0/I2S0_RX0 to one GSM, connect the I2S0_TX1/I2S0_RX1 to another GSM, it is okay. For another SAI module I2S1, it is the same as that of I2S0 module.

If the GSM module has to be master, it is another story, you have to use 4 SAI modules to interface. in the case, you have to select the processor with 4 SAI modules, you can refer to i.mx or the other chips.

Hi Xiangjun RongThank for your support.About GSM module, it only have support master mode, so I think shoud choose an MCu support 4 SAI modules.Or another way, can choose 4 small MCU support 2 UART, 1 PCM to connect direct with GSM module before tranfer data to SOC.What do you think about this idea?

Hi Xiangjun RongThanks for your suggestionBut in this MCU series, I cant find and MCU have enough 4 UARTPlease review and help me to solve this problem which may be difficult and waste time for youThanks.

Hi Xiangjun RongBecause IMX MCU is expensive so I decided change GSM module to I2S interface, which may be control with K55/K56 MCU through I2S portBut i checked on K55/K56 only support SAI mode, maybe it can support alternate 4 I2S chanel at same time?Thanks

Sorry about my careless when typing.Exactly is K65/K66 Kinetis version as you suggested on last post.I tried with this link but cannot find a part with 2 SAI/ 4 I2S channelCan you help me to show this part?ThanksNXP Product Selector

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Hi Xiangjun RongI forgot talking with you i need more 4 I2C port when interface with 4 new GSM module So now i need : 4 I2S, 4 I2C, 5/6 UART, 1 USBI have checked on K66 version but i cant fast find I2S/SAI in prodution tool online on webistecan you show me a way to fast find this parametter, now i must download datasheet for onece and checkingThanks

I attached a Kinetis Selector Guide in the last post as the follwoing screenshot, pls open the KINETISKMCUSELGD.PDF, search the I2S key words, check the I2S module number, as far as I know, there are at most 2 SAI modules for Kinetis family.

Hi Xiangjun rongMy GSM module have support both master/slave mode ( config by AT commmand)

Buy i not care about speed sample rate of SAI modules on Kinetis.

My GSM module have highest sample rate is 48Khz, and also support I2S in two mode

So, when I using normal I2S for capture voice or send voice with 48Khz sample rate, the bit clock frequnecy for one module is 48Kx 16bitx2 channel ~ 1.536MHz

so total for 4 module GSM, i must need bit clock about 4x1.536MHz ~ 6.144Mhz

And with Maximum bit clock divider: 512 of SAI module , we need about 6.144Mhz/512 = 12Khz for I2S bitlock form SAI module?And in maximum, 4 module can be working same time, the TDM method does allow it can control same this way?

As you said that the GSM module supports slave mode, and I2S mode or normal mode. I suppose that you use K60 which has two SAI modules:SAI0 and SAI1.

This is the connection:

SAI0_TX_BCLK: GSM0 and GSM1 Receiver bit clock

SAI0_TX_SYNC:GSM0 and GSM1 Receiver Frame clock

SAI0_TX_DATA0: GSM0 Rx

SAI0_TX_DATA1:GSM1 RX

SAI0_RX_BCLK: GSM0 and GSM1 Transmitter bit clock

SAI0_RX_SYNC:GSM0 and GSM1 transmitter Frame clock

SAI0_RX_DATA0: GSM0 Tx

SAI0_RX_DATA1:GSM1 TX

If the GSM module use the same bit clock and frame clock for both transmitter and receiver, you just need to conncet SAI0_TX_BCLK to SAI0_RX_BCLK, SAI0_TX_SYNC to SAI0_RX_SYNC, while set the SAI0 transmitter as master, set SAI0 receiver as slave, it is okay.

For SAI1 module, it is connected to GSM2 and GSM3, pls refer to SAI0 connection.

Regarding the mode, from the description you gave, the GSM module supports mono mode, in other words, it only supports single channel. If you use I2S mode, you can fill the second channel with a dummy data.

If you use I2S mode, each frame convers two channel(first channel is valid data, second channel is dummy data), assume one bit frame clock, sample rate is 48KHz, the required I2S bit clock frequency:

48KHz*17bits*2=1.632MHz. The bit clock frqeuency is not related to data channel, it is only related to slots number

If you can generate 1.632MHz or integer times frequency of 1.632MHz as MCLK, it is okay.

From your description, the GSM module only support I2S or normal mode, i do not know if it can support TDM mode.

In I2S mode, there are only two slots: first slot and second slot.

in normal mode, there are multiple slots, but only first slot includes valid data, the other slots includes dummy data.

In TDM mode, there are multiple slots, all slots includes valid data, but the GSM must be set to know which slot is a valid slot for itself.

I think there can be one slot in normal mode for GSM module, in the case, the required bit clock is 48KHz*17bits=816KHz

About connection for I2S on GSM module , it have 4 wire, I2S_TXD,_RXD,_CLK, _WASo I2S_WA will be SAI0/1_TX_SYNC pinI intend to use I2S switch for control beween SAI0 will be connect with GMS0 or GSM1, SAI1 will be connect with GMS2 or GSM3 My issue in this case all GSM module will be transmit/receive data or random will have 1 module transmit& 3 module receive, or with K60 on same time, so I intend to use switch for connection with K60 in one time slot.

Really 2 SAI channel can care of this?So the last issue maybe confirm about way to control bettween GSM modules in this case .Thanks